When many holes are machined into a surface of a workpiece by using a rotating tool such as, for example, a drill, a tool T is positioned at a position corresponding to a hole H1 and then fed toward a workpiece W in the direction of the rotational axis of the tool T (Z-axis direction) (path 1) in order to machine the hole H1, as illustrated in FIG. 5. Then, the tool T is moved in the Z-axis direction so as to be separated from the workpiece W, and is removed from the hole H1 (path 2). After the end of the tool T is separated from the workpiece W, the tool T is fed, by X-axis and Y-axis feed devices, to a position corresponding to a succeeding hole H2 to be formed (path 6). After arriving at the position corresponding to the succeeding hole H2, the tool T is re-fed in the Z-axis direction toward the workpiece W to form the hole H2 (path 4). As described above, in movement of a tool from a machining site to a succeeding machining site with respect to a workpiece, it takes time to move the tool since it is necessary to temporarily stop the feed between the path 2 and the path 6 as well as between the path 6 and the path 4 in the example of FIG. 5 when the feed direction of the tool is changed.
Patent Literature 1 describes a machine tool for moving a movable body by using two drive devices, for example, an X-axis drive device and a Y-axis drive device, so as to shorten movement time. The machine tool of Patent Literature 1 is configured so that when it is necessary to change the direction of movement of a movable body to any one axial direction at at least one point in the case of moving the movable body under two-axis control, the movable body is gently accelerated or decelerated at not more than a maximum acceleration or deceleration rate in the axis direction to which the direction of the movement of the movable body is changed, and another drive device moves the movable body at the maximum lower limit rate, after the movable body arrives at the point of the change of the direction of the movement of the movable body.